My advisor suggested that at my stage of the game, 8 properties, it likely made more sense to keep the extra money available or in the business to use as emergency funds or to accumulate for another down payment.

Property Type: Do you prefer residential, commercial, or mixed-use properties?

You need to meet more real investors to match the overviews you are getting from books.

It seems you are the only person who understood the question wanting to know what a seller makes (not even sure how or why you think that).As a typical part of the DD process it is not uncommon to ask for property/entity tax returns.

I have intention to "house hack" a 2-4 unit property, which we will then hold as a rental property. 

If they've owned the property for 15yrs, probably a better chance of owner fatigue than someone only having it for 2 yrs.

The report makes a big deal about the neighborhood and local economy in addition to the property itself.

Outside of wholesaling, I'd like to explore BRRR, Fix-n-Flips, and eventually Multifamily properties. 

I have decided to partner up with another investor to buy this property together.

I would say that a great thing any flipper can do is develop their own off-market properties.